package Pack1;
//此类为父类
class Animal {
}
//Dog类继承Animal类
class Dog extends Animal {
}
//Cat类继承Animal类
class Cat extends  Animal {
}
//可以继承单个父类
class Fish extends Animal {

}
//不能继承多个父类
//class Me extends Animal,Dog {
//}

//final class Father {
//}
//class Son extends Father {
//}

public class Test3 {
    public static void main(String[] args) {
        final int a = 10;
//        a = 20;
    }
}
